Long-length oligonucleotide microarrays

Abstract

A method for producing a DNA microarray for biological assays comprising a plurality of biosites located on a solid substrate. Each biosite has at least one set of chemically presynthesized, oligonucleotides of medium to long lengths attached to the substrate by predominantly non-covalent means, such as electrostatic, hydrophobic, hydrogen bonding, van der waal forces, etc. The oligonucleotides exhibit no predetermined spatial orientation on the substrate surface. The oligonucleotides are chemically unmodified having a length of about 30 bases or longer. Preferably, the oligonucleotides are from about 45 bases to 85 bases, but some embodiments may include very long oligonucleotides of over 100 bases.

We claim:  
     
         1 . An array for biological assays comprising a solid substrate having a plurality of biosites, each biosite having at least one set of chemically pre-synthesized, oligonucleotides of a length of about 30 bases or longer and attached to said substrate by predominantly non-covalent means.  
     
     
         2 . The array according to  claim 1 , wherein said oligonucleotides exhibits no predetermined spatial orientation upon said substrate.  
     
     
         3 . The array according to  claim 1 , wherein said oligonucleotides are unmodified.  
     
     
         4 . The array according to  claim 1 , wherein said oligonucleotides have a length in a range from about a 30-mer to about a 80-mer.  
     
     
         5 . The array according to  claim 2 , wherein said oligonucleotides have a length in a range from about a 50-mer to about a 75-mer.  
     
     
         6 . The array according to  claim 1 , wherein said oligonucleotides have a length in a range from about a 80-mer to about a 180-mer.  
     
     
         7 . The array according to  claim 1 , wherein said oligonucleotides are attached to a dendrimer.  
     
     
         8 . The array according to  claim 1 , wherein said substrate has a surface made from a material selected from the following: plastics, glass, SiO 2 , silanes, hydrogels, gold or platinum.  
     
     
         9 . The array according to  claim 1 , wherein said substrate has a surface made from a material selected from the following: polyvinyl, polystyrene, polypropylene, polyester plastics.  
     
     
         10 . The array according to  claim 1 , wherein said substrate has a surface made from glass.  
     
     
         11 . An array for biological assays comprising a set of chemically pre-synthesized, single-stranded oligonucleotides, having a length of about 60 bases and longer, attached to multi-armed molecule that is in turn attached to a substrate by predominantly non-covalent means, wherein said oligonucleotides exhibits no predetermined spatial orientation upon said substrate.  
     
     
         12 . The array according to  claim 11 , wherein said oligonucleotides have a length of in a range from about 70 bases to about 80 bases.  
     
     
         13 . The array according to  claim 11 , wherein said oligonucleotides have a length of about 100 bases to about 150 bases.  
     
     
         14 . The array according to  claim 11 , wherein said substrate has a surface made from a material selected from the following: plastics, glass, SiO 2 , silanes, hydrogels, gold or platinum.  
     
     
         15 . A method for fabricating microarrays, the method comprising: providing at least one chemically synthesized oligonucleotide having a length of about 30 bases and greater, affixing said oligoneucleotide to a substrate by a non-covalent means in a manner such that said oligonucleotide exhibits no predetermined orientation upon said substrate.  
     
     
         16 . The method according to  claim 15 , wherein said oligonucleotide is not chemically modified.  
     
     
         17 . The method according to  claim 15 , wherein said substrate possesses an electrostatic charge.  
     
     
         18 . The method according to  claim 15 , wherein said oligonucleotide has a length of about 70 bases or greater and is affixed directly to said substrate.  
     
     
         19 . The method according to  claim 15 , wherein said first oligonucleotide has a length of in a range from about 100 bases to about 150 bases.  
     
     
         20 . The method according to  claim 15 , wherein said substrate has a surface made from a material selected from the following: plastics, glass, SiO 2 , silanes, hydrogels, gold or platinum.